Method for Operating a Mobile Wireless Network

ABSTRACT

A method of operating a mobile wireless network is described to ensure proper function of protocol entities during the transmission of data units between two wireless stations of the mobile wireless network. In this case, user data is assembled by a first convergence protocol layer of the first wireless station into at least one first data unit, particularly a packet data unit, before transmission to a second convergence protocol layer of a second wireless station, particularly on the same protocol level, with the user data being supplied to the first convergence protocol layer by at least one user in a network layer. At least one protocol entity of the first convergence protocol layer is configured as a function of a configuration request received by the second wireless station, in order to form the at least one first data unit from the data received from the at least one user and to transmit it through a carrier to a link control layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/589,136 filed Oct. 19, 2009, which is a continuation of U.S. patentapplication Ser. No. 11/825,330 filed Jul. 6, 2007, which issued as U.S.Pat. No. 7,609,726 on Oct. 27, 2009, which is a continuation of U.S.patent application Ser. No. 10/111,511, filed Sep. 17, 2002, whichissued as U.S. Pat. No. 7,245,636 on Jul. 17, 2007 (which is a U.S.national stage application of PCT international application numberPCT/DE00/03247) and which claims the benefit of priority of PCTinternational application number PCT/DE00/03247 having an internationalfiling date of Sep. 19, 2000, and designating the United States ofAmerica, which claims priority to German patent application DE 19950653,the entire contents of all of the foregoing are hereby expresslyincorporated herein by reference.

This application is related to U.S. patent application Ser. No. ______Attorney Docket No. 60851/395881) filed concurrently herewith, theentire contents of which are hereby expressly incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to a method for operating a mobilewireless network.

BACKGROUND INFORMATION

A method for operating a mobile wireless network is described in GermanPublished Patent Application No. 199 44 334 in which data is assembledinto at least one unit, particularly a packet data unit, by a firstconvergence protocol layer before transmission to a second convergenceprotocol layer, particularly on the same protocol level, with the databeing supplied to the first convergence protocol layer by a user in anetwork layer.

SUMMARY OF THE INVENTION

In an example method according to the present invention at least oneprotocol entity of the first convergence protocol layer may beconfigured as a function of a configuration request received from asecond wireless station in order to form at least one first data unitfrom the data received from the at least one user and may transmit it toa link control layer through a carrier. In this manner, protocolentities may be generated in the first wireless station whose settingsand function may be identical to the settings and function ofcorresponding protocol entities of the second wireless station, so thatproper functioning of the protocol entities may be ensured during thetransmission of the data units between the two wireless stations.

The example method may be refined and improved.

Using the configuration request, at least one selection for alternativesettings for the protocol entity, which may be supported by the secondwireless station, may be predetermined. In this manner, the firstwireless station may select the most favorable setting for a firstwireless device from the alternative settings as a function of its owncapabilities or its own output range and/or as a function of a userpreset.

A confirmation signal may be transmitted from the first wireless stationto the second wireless station in which the setting selected andperformed by the first wireless station is communicated to the secondwireless station. In this manner, the second wireless station mayconfigure its at least one protocol entity as a function of the settingperformed for the first wireless station, in order to ensure properfunctioning of the protocol entities during the transmission of the dataunits between the two wireless stations.

During the configuration, a protocol entity ID may be specified, throughwhich the protocol entity is referenceable. In this manner, the protocolentity may be accessed rapidly and directly for later reconfigurationsand to release the protocol entity.

The protocol entity ID may be specified so that it corresponds to the IDof the carrier assigned to it. In this manner, the transmission of anadditional information element for identifying the protocol entity maybe eliminated, and therefore transmission bandwidth may be saved.

A communication may be transmitted from the first wireless station tothe second wireless station, before receipt of the configurationrequest, indicating which settings of the at least one protocol entityare supported by the first wireless station. In this manner, it may beensured that the second wireless station, using the configurationrequest, only specifies to the first wireless station, in a specified orselectable manner, those settings for the configuration of the at leastone protocol entity which are also implementable in the first wirelessstation.

The communication may be transmitted to the second wireless stationtogether with a message about the capabilities and the output range ofthe first wireless station. In this manner, an additional informationelement for the transmission of the communication may be eliminated, andtherefore transmission bandwidth may be saved.

The configuration request, in the case in which a carrier isestablished, reconfigured, or cleared using a carrier configurationmessage, may be inserted into the carrier configuration message. In thismanner, an additional information element for the transmission of theconfiguration request may be eliminated, and therefore transmissionbandwidth may be saved.

The confirmation signal may be inserted into a message issued by thefirst wireless station to acknowledge the establishment or thereconfiguration of the carrier. In this manner, an additionalinformation element for the transmission of the confirmation signal maybe eliminated, and therefore transmission bandwidth may be saved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a mobile wireless network having two wireless stations.

FIG. 2 shows a protocol layer sequence for the two wireless stations.

FIG. 3 shows a detail from the protocol layer sequence of a first of thetwo wireless stations.

FIG. 4 shows a first variation over time of a signaling exchange betweenthe two wireless stations.

FIG. 5 shows a second variation over time of a signaling exchangebetween the two wireless stations.

FIG. 6 shows a message element for communicating the capabilities or theoutput range of the first wireless station.

FIG. 7 shows a carrier configuration message.

FIG. 8 shows an acknowledgment message.

DETAILED DESCRIPTION

In FIG. 1, 30 identifies a mobile wireless network in which a firstwireless station 15 and a second wireless station 16 are located. Secondwireless station 16 is connected in this case to a network unit 80,which offers services for subscribers in mobile wireless network 30 andoperates mobile wireless network 30. First wireless station 15 is, inthis example, a subscriber of mobile wireless network 30, for example inthe form of a mobile telecommunication terminal or a mobile station,particularly in the form of a mobile telephone. In the following, firstwireless station 15 is to be implemented as a mobile station. Secondwireless station 16 is, in this example, a base station of mobilewireless network 30. However, it may not be relevant for the presentinvention whether first wireless station 15 and/or second wirelessstation 16 is a subscriber or a base station of the mobile wirelessnetwork. In this case, mobile wireless network 30 may have further basestations and subscribers, which are not, however, illustrated in FIG. 1.

Mobile wireless network 30 may, for example, be operated according to aGSM standard (Global System for Mobile Communications) or according to aUMTS standard (Universal Mobile Telecommunications System) or the like.

The present invention relates to a packet data convergence protocol formobile wireless networks. The present invention suggests functionalitieswithin a convergence protocol layer 1, 2 as shown in FIG. 2, which maybe used in, for example, a mobile wireless system according to the UMTSstandard (Universal Mobile Telecommunications System) or also in amobile wireless system according to the GSM standard. In the following,it may be assumed for exemplary purposes that mobile wireless network 30is operated according to the UMTS standard.

The convergence protocol used according to the UMTS standard is referredto in this case as PDCP (Packet Data Convergence Protocol).

The functionalities of the UMTS mobile wireless system may be dividedinto layers, as may also be the case in the GSM mobile wireless systemshown in FIG. 2. Various protocols may be specified within the layerswhich may make various services available to each of the higher layersand which may make use of the services offered by lower-lying layers.Each protocol exists in this case at least two times within the mobilewireless system, namely in at least two units, with the units each lyingin the same layer. In this case, mobile station 15 represents a first ofthe two units. Base station 16 represents a second of the two units. Thelayer hierarchy described is classified into a user level and a controllevel in this case. The user level may also be referred to as a userplane and the control level may also be referred to as a control plane.Protocols in which user data is transported are assigned to the userlevel in this case. Protocols in which control data is transported andpartially generated are assigned to the control level. The layer orprotocol hierarchy of the user level may be relevant for this presentinvention since the convergence protocol layer lies in the user leveland provides services for user data transport. User data which isgenerated by applications and packets and is to be transmitted in apacket-oriented manner is initially transferred from the appropriateapplication to a transport layer protocol in a transport layer. The TCP(Transmission Control Protocol) and the UDP (User Datagram Protocol) maybe conventional in this regard. However, other transport layer protocolsor a transparent transport layer may also be possible, through which theuser data to be transmitted is relayed transparently without using atransport layer protocol. Transport layer protocols may be used for thepurpose of securing the packet data for transport through mobilewireless network 30, which is used in this case as a packet datanetwork, and for attaching the desired routing information to it. Thetransport layer may use services of a network protocol in a networklayer lying underneath the transport layer. The network layer isillustrated in FIG. 2 and is identified using the reference number 5 formobile station 15 and using the reference number 6 for base station 16.The network protocols are, as described, referred to as PDP (Packet DataProtocol). The transport layer uses the services of the PDPs in order totransmit the user data. Example PDPs of network layer 5, 6 may includeIP (Internet Protocol) and the X.25 protocol. Both the network and thetransport protocols may attach control data to the user data, forexample in the form of a TCP/IP header. The UMTS-specific protocols maylie underneath network layer 5, 6. Data about the data link used by thePDP is stored using each PDP in mobile wireless network 30 and in aterminal of the mobile wireless network which communicates with mobilewireless network 30, for example in mobile station 15. This data may,for example, contain parameters about quality of service QOS and isreferred to as PDP context. It may be possible to operate a PDPsimultaneously using different contexts, with the contexts onlydiffering in the parameters for quality of service QOS. Therefore, in aterminal, an IP protocol having an IP address may be operated once usinga first parameter for quality of service QOS and once using a secondparameter for quality of service QOS. PDP contexts may, however, also bebased on different network protocols. Thus, for example, three differentnetwork protocols may run in one terminal: two IP protocols havingdifferent IP addresses and one X.25 protocol.

Each of these PDP contexts is illustrated as an independent block innetwork layer 5, 6 above convergence protocol layer 1, 2 and isindicated in FIG. 3 for mobile station 15 using reference numbers 21 and22. In this case, PDP contexts 21, 22 represent users of convergenceprotocol layer 1, 2 shown in FIG. 3 lying underneath network layer 5, 6.In FIG. 2, the convergence protocol layer for mobile station 15 isindicated using reference number 1 and the convergence protocol layerfor base station 16 is indicated using reference number 2.

The PDCP, whose task is to prepare the data to be transmitted betweenmobile station 15 and base station 16 for efficient UMTS transmission,tailors the user data which comes from a PDP context for transmissionvia an air interface, in that it optionally compresses the user dataand/or the control data or protocol control information added to theuser data and combines or multiplexes possible packet data streams fromdifferent PDP contexts 21, 22, which require the same transmissionquality, into one packet data stream.

In the layer model of the UMTS mobile wireless system, an RLC linkcontrol layer (Radio Link Control) is located underneath convergenceprotocol layer 1, 2 provided for forming the PDCP, which is indicatedfor mobile station 15 using reference number 10 and for base station 16using reference number 11 in FIG. 2 and which optionally correctstransmission errors of the air interface, in that it requests any faultypackets to be resent on the receiver end and resends them on thetransmitter end. Furthermore, RLC link control layer 10, 11 optionallyensures that the sequence of the data packets is maintained duringtransmission and segments the data packets into RLC-PDUs (RLC PacketData Units), whose length is tailored to the transmission channels used.

A data carrier, which may also be referred to as a radio bearer or RB,and which provides RLC link control layer 10, 11 lying underneathconvergence protocol layer 1, 2, is then used for the transmission ofany of the multiplexed packet data streams from various PDP contexts 21,22.

Convergence protocol layer 1, 2 has PDCP protocol entities 35 as shownin FIG. 3, each of which may contain multiple compression algorithms 50,51. Multiple PDP contexts 21, 22 may be connected to one PDCP protocolentity 35; however, one PDP context 21, 22 may only be connected to onePDCP protocol entity 35. Each PDCP protocol entity 35 uses one carrier45, which may also be referred to as a radio bearer. A radio bearer isthe link between a PDCP protocol entity 35 and an entity of underlyingRLC link control layer 10, 11, via which the data is relayed fromconvergence protocol layer 1, 2 to RLC link control layer 10, 11.Conventional compression algorithms, such as those described in thepublication RFC 1144 “Compressing TCP/IP Headers for Low Speed SerialLinks” for TCP/IP protocols (TCP=Transmission Control Protocol;IP=Internet Protocol) and in the publication RFC 2507 “IP HeaderCompression” for UDP/IP protocols (UDP=User Datagram Protocol), arebased on the establishment and use of codebooks, in which codes arestored in the form of tables, with which the user data and/or protocolcontrol information to be transmitted is coded and/or compressed incorresponding PDCP protocol entity 35 of the transmitting wirelessstation and to which reference is made in the user data and/or protocolcontrol information compressed in this manner. The codebooks used mustalso be available in the decompressor of the receiving wireless stationin order to allow decoding.

In order to ensure proper functioning of PDCP protocol entities 35,compression algorithms 50, 51, their compression parameters, such as thenumber of codes to be stored in the compressor and decompressor incorresponding codebooks, and the multiplexing information of bothconvergence protocol layers 1, 2 in mobile station 15 and in basestation 16 may need to be identical. In this case, the multiplexinginformation indicates which PDP contexts 21, 22 supply their packet datastreams to corresponding PDCP protocol entity 35 for multiplexing.Compression algorithms 50, 51, the compression parameters, and themultiplexing information represent PDCP protocol entity parameters,which may also include further parameters, such as information aboutcarrier 45 to be used by corresponding PDCP protocol entity 35. Beforesetup of a new PDCP protocol entity 35, a handshake procedure of bothwireless stations 15, 16 about the PDCP protocol entity parameters to beconfigured is performed. This handshake procedure is performed in thecontrol level by an RRC (Radio Resource Control), with radio resourcecontrol RRC being identified in FIG. 2 for mobile station 15 usingreference number 95 and for base station 16 using reference number 96.

RLC link control layer 10, 11 uses the services of the underlying MAClayer (Medium Access Control) in order to transmit the RLC-PDUs. The MAClayer is indicated in FIG. 2 for mobile station 15 by reference number85 and for base station 16 by reference number 86 and ensures the accessto the actual transmission medium, selects suitable transport formats,and multiplexes the various RLC-PDUs onto suitable transport channels,which are mapped onto the assigned physical channels in the underlyingphysical layer, which is indicated in FIG. 2 for mobile station 15 byreference number 90 and for base station 16 by reference number 91. Thelayer hierarchy or protocol hierarchy is described in the publication“Radio Interface Protocol Architecture”, 3 GPP TS 25.301. Some of thelayers described, i.e., physical layer 90, 91, MAC layer 85, 86, RLClink control layer 10, 11, and convergence protocol layer 1, 2, alsohave a direct link to radio resource control RRC. This link is used totransmit status information to radio resource control RRC 95, 96 and toallow radio resource control RRC 95, 96 to configure the otherprotocols.

Data to be transmitted between mobile station 15 and base station 16runs from top to bottom through the layer sequence described. Datareceived runs from bottom to top through the layer sequence described.

A protocol for controlling radio resource control RRC 95, 96 isdescribed in the publication “RRC Protocol Specification”, 3 GPP TSG RANWG2, TS 25.331 v1.4.2 and is referred to in the following as RRCprotocol. The objects of this RRC protocol may include, among otherthings, the configuration of the individual layers, negotiation ofparameters for the configuration of the layers with the peer RRC layer,and establishment and release of connections between mobile station 15and mobile wireless network 30 and/or, acting as mobile wireless network30 in this example embodiment, to base station 16. The peer RRC layerrepresents, in this case, a layer of radio resource control RRC 95, 96on the same protocol layer level as the layer of mobile station 15and/or base station 16 to be configured. The parameters for configuringthe individual layers are exchanged in messages between the peer RRClayers of mobile station 15 and base station 16 in regard to therespective layer to be configured.

The signaling described in the publication “RRC Protocol Specification”cited may not include the negotiation of the PDCP protocol entityparameters, i.e., neither the negotiation of compression algorithms 51,52 and their compression algorithms for PDCP protocol entities 35, forexample, nor the configuration of the multiplexing of the packet datastreams of multiple PDP contexts 21, 22 in convergence protocol layer 1,2.

In FIG. 3, a detail from the layer sequence for mobile station 15 isillustrated as an example.

In FIG. 3, network layer 5, convergence protocol layer 1, and linkcontrol layer 10 of mobile station 15 are illustrated. In this case, asshown in FIG. 3, each PDP context 21, 22 uses the services ofconvergence protocol layer 1 at a respective access point 101, 102assigned to it, which may also be referred to as a network layer serviceaccess point (NSAP). Each of these access points 101, 102 is assigned anidentifier, for example an NSAPI (Network Layer Service Access PointIdentifier), which uniquely identifies assigned PDP context 21, 22.Currently, for GSM a maximum of 16 NSAPs may be simultaneously providedin a mobile station 15. For UMTS, the number of PDP contexts which maysimultaneously exist in a mobile station may not have yet beenspecified. The links of link control layer 10 are used by convergenceprotocol layer 1 via service access points, which are may also bereferred to as SAP (service access point). An identifier RB identity(radio bearer identity) is assigned to each of the individualconnections to the SAPs in order to identify the individual connectionsbetween convergence protocol layer 5 and link control layer 10. In thiscase, each service access point offers a specific quality of service ortransmission QOS and, in the GSM mobile wireless system, a maximum offour different service access points, and therefore four different linksin link control layer 10 having different quality of transmission QOS,may be provided. In the UMTS mobile wireless system, for example, threedifferent service access points, each having different links in linkcontrol layer 10 with different qualities of transmission QOS, may beprovided, without being restricted to this example. In order to allowconvergence protocol layer 1 to be able to relay data packets arrivingor received at one of the service access points to the correct receiverand/or to the correct PDP context after decompression of the user dataand/or the protocol control information, the data packets may have anidentifier of the receiving PDP context, i.e., the receiving user ofconvergence protocol layer 1, attached by the transmitter. The NSAPI maybe used as an identifier for this purpose, which may be, for example,attached to each data packet on the transmitter end as a 4-bit value.

The links to the service access points described are each implemented bya carrier which is, as described, also referred to as a radio bearer. Aradio bearer is, as described, the link between a PDCP protocol entity35 and an entity of underlying RLC link control layer 10, 11, via whichthe data from convergence protocol layer 1, 2 is relayed to RLC linkcontrol layer 10, 11. In FIG. 3, carrier 45 is illustrated acting as theservice access points, which, acting as the PDCP protocol entitieslocated in convergence protocol layer 1, connects PDCP protocol entity35 to an entity of RLC link control layer 10, not illustrated in FIG. 3.PDCP protocol entity 35 of convergence protocol layer 1 described forexemplary purposes includes, in this case, as shown in FIG. 3, a datacompression algorithm 51 which compresses the user data received fromnetwork layer 5. A data decompression algorithm, not shown in FIG. 3, isassociated with data compression algorithm 51. The data decompressionalgorithm decompresses user data received from link control layer 10 andtherefore ultimately from base station 16. At the same time, it reversesa data compression in accordance with assigned data compressionalgorithm 51. PDCP protocol entity 35 of convergence protocol layer 1further includes a protocol control information compression algorithm50, which is also referred to in the following as first compressionalgorithm 50 and which compresses the protocol control informationreceived from network layer 5 with the user data and/or generated inconvergence protocol layer 1 for the user data received. A protocolcontrol information decompression algorithm, not shown in FIG. 3, whichdecompresses the protocol control information received from link controllayer 10 and thus reverses a compression according to assigned protocolcontrol information compression algorithm 50, is associated in acorresponding way with protocol control information compressionalgorithm 50.

A first PDP context 21 is connected, via a first access point 101assigned to it, to protocol control information compression algorithm 50and an associated protocol control information decompression algorithm.In the following, the compression and decompression algorithmsassociated with one another are viewed as a unit to simplify thedescription and are referenced by the corresponding compressionalgorithm as a substitute. Thus, protocol control informationcompression algorithm 50 is connected via data compression algorithm 51,which is also referred to in the following as second compressionalgorithm 51, to carrier 45.

A second PDP context 22 is directly connected, via an access point 102assigned to it, to data compression algorithm 51, which is connected tocarrier 45, as described. The remaining PDP contexts of network layer 5are not shown in FIG. 3 for reasons of clarity, nor are further PDCPprotocol entities of convergence protocol layer 1 and further carriers.

The present invention may include procedures which allow the negotiationof PDCP protocol entity parameters and the establishment of PDCPprotocol entities between two devices of mobile wireless network 30, inthis example between mobile station 15 and base station 16, whichcooperate with network unit 80, for example a radio network controller(RNC), and may therefore be understood as acting as a network entity.

In this case, a procedure in which base station 16 receives acommunication 60, shown in FIG. 4, from mobile station 15 about thesettings supported by mobile station 15 of PDCP protocol entity 35 to beconfigured of mobile station 15 is at the beginning of the negotiations.In this example, the configuring of PDCP protocol entity 35 illustratedin FIG. 3 is described as an example. Multiple PDCP protocol entities ofmobile station 15 may, of course, be configured simultaneously in acorresponding manner.

Directly before the initial setup of PDCP protocol entity 35, basestation 16, shown in FIG. 4, sends a first configuration request 40 tomobile station 15, in which the initial setup of PDCP protocol entity 35is initiated. The PDCP protocol entity parameters which base station 16has selected taking into consideration the settings supported by mobilestation 15 of PDCP protocol entity 35 to be configured are contained inthis first configuration request 40. First configuration request 40 mayalso be referred to as the PDCP Establishment Request.

Mobile station 15 may now establish PDCP protocol entity 35 using thePDCP protocol entity parameters received in first configuration request40 from base station 16. After this establishment, mobile station 15acknowledges the establishment and therefore signals to base station 16,using a first confirmation signal 55, that PDCP protocol entity 35 isready to receive and/or transmit data. This first confirmation signal 55may also be referred to as the PDCP Establishment Confirm.

It is alternatively or additionally possible that first configurationrequest 40 includes a selection of settings and/or PDCP protocol entityparameters supported by base station 16 for forming PDCP protocol entity35, so that mobile station 15 may also, after receiving firstconfiguration request 40, select on its part the PDCP protocol entityparameters from the predetermined selection in order to adjust PDCPprotocol entity 35 as optimally as possible to the capabilities and theoutput range, and possibly also to user presets. Using firstconfirmation signal 55, which mobile station 15 then sends to basestation 16, the PDCP protocol entity parameters selected by mobilestation 15 are communicated to base station 16.

If the establishment of PDCP protocol entity 35 fails, a correspondingmessage about the failure of the establishment may be transmitted frommobile station 15 to base station 16 instead of first confirmationsignal 55. This message may be referred to as a “PDCP EstablishmentFailure” message.

Communication 60 contains, for example, information about compressionalgorithms 50, 51 supported by mobile station 15, their compressionparameters used, and the multiplexing methods which are possible inmobile station 15, i.e., the maximum number of PDP contexts 21, 22 andthe possible number of carriers used by convergence protocol layer 1 ofmobile station 15.

First configuration request 40 contains information about which PDPcontexts 21, 22 access PDCP protocol entity 35 to be set up and whichcarrier is to be used by this PDCP protocol entity 35. Furthermore,either first configuration request 40 contains specified presets aboutcompression algorithm(s) 50, 51 to be used and the compressionparameters to be used for this purpose or first configuration request 40contains a selection of possible compression algorithms 50, 51 and/or aselection of compression parameters, from which mobile station 15 mayselect one or more suitable compression algorithms 50, 51 and theircompression parameters.

First confirmation signal 55 then contains either only the informationthat corresponding PDCP protocol entity 35 was established or additionalinformation about compression algorithm(s) 50, 51 selected and its/theircompression parameters.

If the establishment of PDCP protocol entity 35 fails, a “PDCPEstablishment Failure” message, which may contain information about thereason for the failed establishment, is transmitted by mobile station 15to base station 16 instead of first confirmation signal 55.

First configuration request 40 and first confirmation signal 55additionally contain a PDCP protocol entity ID, with which PDCP protocolentity 35 may later be referenced in order to release or reconfigure it.The function of the PDCP protocol entity ID may also be assumed by theID for carrier 45, as described in the publication “RRC ProtocolSpecification” cited, which may also be referred to as “RB identity,”since a PDCP protocol entity may be assigned to one and only onecarrier.

After PDCP protocol entity 35 is established, it may be possible toreconfigure it. For this purpose, base station 16 sends a secondconfiguration request 41 shown in FIG. 5, which indicates how PDCPprotocol entity 35 is to be reconfigured, to mobile station 15. Secondconfiguration request 41 may also be referred to as a “PDCP reconfigurerequest” message. This second configuration request 41 may be used forvarious purposes and correspondingly may contain various items ofinformation, but the ID of the PDCP protocol entity/entities to bereconfigured is contained in second configuration request 41.

In order to modify the multiplexing function of established PDCPprotocol entity 35 described in this example, it may be advisable toattach information about one or more new PDP contexts, whose packet datastreams are to be multiplexed onto carrier 45 used by PDCP protocolentity 35, in convergence protocol layer 1 of mobile station 15 tosecond configuration request 41, in addition to the packet data streamsof already present PDP contexts 21, 22.

If one or more existing PDP contexts 21, 22 are to use a carrier havingother properties, for example having another quality of transmissionQOS, it may be advisable to attach information about the PDP context(s)to second configuration request 41, whose packet data streams are to bemultiplexed onto a carrier having the desired properties in convergenceprotocol layer 1 of mobile station 15 by existing PDCP protocol entity35.

If PDCP protocol entity 35 is to use one or more other or additionalcompression algorithms for compressing the user data or the protocolcontrol information, it may be advisable to attach information aboutthis or these new compression algorithm(s) to second configurationrequest 41.

Second configuration request 41 may be acknowledged by mobile station 15by a second confirmation signal 56 shown in FIG. 5, which may also bereferred to as a “PDCP Reconfigure Confirm” message, in order tocommunicate the successful change of the configuration to base station16.

If mobile station 15 is given the possibility, after receipt of secondconfiguration request 41, as also described for first configurationrequest 40, of selecting on its part the PDCP protocol entity parametersfrom a selection made available by base station 16, in this manner thePDCP protocol entity parameters appropriately selected and set by mobilestation 15 may be contained in second confirmation signal 56 in a mannercorresponding to that described for confirmation signal 55.

If the reconfiguration of PDCP protocol entity 35 fails, then in thismanner, as described, a corresponding message about the failure, whichmay also be referred to as a “PDCP Reconfiguration Failure” message, maybe transmitted back from mobile station 15 to base station 16 instead ofsecond confirmation signal 56. The reason for the failure may becontained in this message.

Established PDCP protocol entity 35 may also be released again. Thisprocedure may also be understood as a configuration in this exampleembodiment, like the establishment and the reconfiguration of PDCPprotocol entity 35. For this purpose, base station 16 shown in FIG. 5sends a third configuration request 42 to mobile station 15, whichcontains the PDCP protocol entity identification and after whose receiptmobile station 15 releases PDCP protocol entity 35. Third configurationrequest 42 may also be referred to as a PDCP Release Request.

Third configuration request 42 may be acknowledged by mobile station 15by a third confirmation signal 57, which may also be referred to as a“PDCP Release Confirm” message, in order to communicate the successfulrelease of PDCP protocol entity 35 to base station 16.

If the release of PDCP protocol entity 35 fails, then instead of thirdconfirmation signal 57, a message about the failure of the release maybe transmitted back from mobile station 15 to base station 16, which mayalso be referred to as a “PDCP Release Failure” message and which maypossibly also contain information about the reason for the failure.

The procedures described here may, for example, all be implemented asdescribed by a protocol for controlling the wireless resources, whichmay also be referred to as an RRC protocol. The RRC protocol may alreadybe partially specified in the UMTS standard in accordance with thepublication “RRC Protocol Specification” cited already which may containprocedures for establishing and releasing and for reconfiguring carriersor RBs. In these procedures, messages are sent from base station 16 tomobile station 15 and vice-versa.

In the case in which PDCP protocol entity 35, described here as anexample, is established, released, or reconfigured at the same instantas assigned carrier 45, it may be advisable to integrate communications60, configuration requests 40, 41, 42, confirmation signals 55, 56, 57,and messages about the failure of the respective configuration of PDCPprotocol entity 35 described above into the RRC messages already definedin accordance with the publication “RRC Protocol Specification” cited.This may be accomplished as follows:

First configuration request 40 for establishing PDCP protocol entity 35is inserted into the “Radio Bearer Setup” message described from thepublication “RRC Protocol Specification” cited. Using this “Radio BearerSetup” message, a new carrier, in this example carrier 45 shown in FIG.3, is established. Since one and only one PDCP protocol entity may beassigned to each carrier and one PDCP protocol entity 35 is also onlyconnected to one carrier, PDCP protocol entity 35 is established usingcarrier 45. Therefore, the PDCP protocol entity parameters for this PDCPprotocol entity 35 may additionally be contained in the “Radio BearerSetup” message.

The establishment of new carrier 45 is confirmed by mobile station 15using the “Radio Bearer Setup Complete” message in accordance with thepublication “RRC Protocol Specification” cited. This “Radio Bearer SetupComplete” message may also assume the function of first confirmationsignal 55 described above. If mobile station 15 is, as described, giventhe possibility, after receipt of first configuration request 40, ofselecting on its part the PDCP protocol entity parameters and ofcorrespondingly setting and/or configure PDCP protocol entity 35, theinformation about the PDCP protocol entity parameters selected. In thismanner may be attached to the “Radio Bearer Setup Complete” message.

If the establishment of new carrier 45 fails, mobile station 15transmits, in accordance with the publication “RRC ProtocolSpecification” cited, a “Radio Bearer Setup Failure” message to basestation 16. If the establishment fails due to a PDCP protocol entity 35which is unable to be created, e.g., due to PDCP protocol entityparameters not supported by base station 16 or mobile station 15,corresponding information about the reason for the failure of theestablishment of PDCP protocol entity 35 may be attached to the “RadioBearer Setup Failure” message.

To reconfigure carrier 45 described in this example, in accordance withthe publication “RRC Protocol Specification” cited, the “Radio BearerReconfiguration” message is transmitted from base station 16 to mobilestation 15. Information corresponding to second configuration request 41described above may be attached to this message, in order to also modifythe PDCP protocol entity parameters of corresponding PDCP protocolentity 35.

In order to confirm the changes in carrier 45 performed during thereconfiguration, mobile station 15 transmits the “Radio BearerReconfiguration Complete” message described in the publication “RRCProtocol Specification” cited as an answer-back to base station 16. Ifmobile station 15 is given the possibility, after receipt of secondconfiguration request 41, of selecting and setting the PDCP protocolentity parameters in the manner described on its part, so that PDCPprotocol entity 35 is modified, i.e., reconfigured, the informationabout the PDCP protocol entity parameters selected may be attached tothe “Radio Bearer Reconfiguration Complete” message.

If the changes and/or the reconfiguration of carrier 45 fails, mobilestation 15 transmits the “Radio Bearer Reconfiguration Failure” messageback to base station 16 in accordance with the publication “RRC ProtocolSpecification” cited. If the error is attributed to a modification ofthe PDCP protocol entity parameters which is unable to be performed, forexample because it is not supported by base station 16 or mobile station15, the reason for this may also be added to the “Radio BearerReconfiguration Failure” message.

For the cases mentioned, the already existing “RB entity” may be used asthe identification for PDCP protocol entity 35 as described, in order tothus dispense with an additional information element.

The cases mentioned here for configuring PDCP protocol entity 35 byestablishing, reconfiguring, and releasing PDCP protocol entity 35 areinitiated in the example embodiment described here by base station 16,but they may also be initiated by mobile station 15.

In the following, the message exchange described between mobile station15 and base station 16 is described in more concrete form. In this case,mobile station 15 includes a digital computer and a mobile wirelessunit, via which the digital computer may transmit and/or receive data toand/or from mobile wireless network 30. This data may, for example, berelayed to and/or from the Internet, which is connected in this exampleembodiment to mobile wireless network 30.

Mobile station 15 announces itself after mobile wireless network 30 isswitched on and sends, at a suitable instant, a “UE CapabilityInformation” message 65 (UE=User Equipment), shown in FIG. 6 andprovided in accordance with the UMTS standard, to mobile wirelessnetwork 30, in which it announces its capabilities and its output rangeto the mobile wireless network. This “UE Capability Information” message65 is [[now]] expanded according to the present invention using a “PDCPcapability” information element, which corresponds to communication 60described. “UE Capability Information” message 65 having “PDCPcapability” information element 60 is shown in FIG. 6. In addition, inFIG. 6, 61 and 62 each indicate an information element of “UE CapabilityInformation” message 65, which represents the capabilities of mobilestation 15 in regard to functions which are independent of PDCP protocolentity 35.

“PDCP capability” information element 60 contains information about themultiplexing and compression capabilities of mobile station 15. In FIG.6, 111 indicates a first sub-information element, which is contained in“PDCP capability” information element 60 and, for example, occupies onebit which indicates whether mobile station 15 supports multiplexing oroccupies multiple bits which indicate how many packet data streams ofdifferent PDP contexts may be multiplexed at maximum onto one carrier.In FIG. 6, 112 indicates a second sub-information element, which iscontained in “PDCP capability” information element 60 andcorrespondingly indicates whether mobile station 15 supports firstcompression algorithm 50. In FIG. 6, 113 indicates a thirdsub-information element which is contained in “PDCP capability”information element 60 and correspondingly indicates whether mobilestation 15 supports second compression algorithm 51. In FIG. 6, 114indicates a fourth sub-information element which is contained in “PDCPcapability” information element 60 and correspondingly indicatescompression parameters for first compression algorithm 50 supported bymobile station 15. In FIG. 6, 115 indicates a fifth sub-informationelement which is contained in “PDCP capability” information element 60and correspondingly indicates compression parameters for secondcompression algorithm 51 supported by mobile station 15. In this case,fourth information element 114 and fifth information element 115represent, for example, the maximum length of the codebooks associatedwith respective compression algorithm 50, 51, i.e., the maximum numberof entries of these codebooks.

Through the transmission of “UE Capability Information” message 65 frommobile station 15 to base station 16, network unit 80 of mobile wirelessnetwork 30 receives information via base station 16 about whichcompression algorithms are supported by mobile station 15. Network unit80 acknowledges the receipt of “UE Capability Information” message 65via base station 16 using a “Capability Information Confirm” message,which is sent to mobile station 15 from base station 16.

On the basis of PDCP protocol entity 35 described in accordance withFIG. 3, it may now be assumed that mobile station 15 supports both firstcompression algorithm 50 and second compression algorithm 51. Asdescribed, second compression algorithm 51 may be, in this case,suitable for the purpose of compressing user data which is to beassembled using the transport layer protocols and the network protocols.Furthermore, in accordance with PDCP protocol entity 35 described inFIG. 3, it may be assumed that mobile station 15 also supports themultiplexing of packet data streams of various PDP contexts 21, 22.

If packet data is now to be transmitted from base station 16 of mobilewireless network 30 to mobile station 15, then for this purpose aconnection is established via the UMTS air interface, i.e., carrier 45and/or a radio bearer RB. For this purpose, base station 16 transmitsthe “Radio Bearer Setup” message as a carrier configuration message 70shown in FIG. 7 as described to mobile station 15, with severalparameters for the establishment of carrier 45 being contained incarrier configuration message 70. According to the present invention,this carrier configuration message 70 is, as shown in FIG. 7, expandedby a “PDCP Info” information element, which corresponds to firstconfiguration request 40 and contains information about how new PDCPprotocol entity 35 which is to be established is to be configured. InFIG. 7, 43 and 44 indicate other information elements which areindependent of the configuration of PDCP protocol entity 35. In FIG. 7,116 indicates a sixth sub-information element which is contained in“PDCP Info” information element 40 and, for example, occupies four bits,which indicate how many different PDP contexts packet data streams areto be multiplexed onto newly established carrier 45. If this number isequal to one, no multiplexing is used. In FIG. 7, 117 indicates aseventh sub-information element which is contained in “PDCP Info”information element 40 and which contains a list which includes theidentifiers for the addressing of PDP contexts corresponding to thenumber indicated in sixth sub-information element 116. In FIG. 7, 118indicates a eighth sub-information element which is contained in “PDCPInfo” information element 40 and which contains the number ofcompression algorithms to be used in PDCP protocol entity 35 to beconfigured. In FIG. 7, 119 indicates a ninth sub-information elementwhich is contained in “PDCP Info” information element 40 and contains alist of these compression algorithms. In FIG. 7, 120 indicates a tenthsub-information element which is contained in “PDCP Info” informationelement 40 and provides either one compression parameter at a time or alist of compression parameters for the compression algorithms indicatedin ninth sub-information element 119.

In an example embodiment for “PDCP Info” information element 40, thevalues contained in the associated sub-information elements may beselected as follows:

sixth sub-information element 116=>1

seventh sub-information element 117=>22

eighth sub-information element 118=>1

ninth sub-information element 119=>51

tenth sub-information element 120=>16.

This means that a PDP context having the identifier 22 uses PDCPprotocol entity 35 for multiplexing its packet data streams onto carrier45, using a compression algorithm having number 51 and codebook length16 in PDCP protocol entity 35. This corresponds to a configuration ofPDCP protocol entity 35 shown in FIG. 3, in which only second PDPcontext 22 is connected, via second access point 102, second compressionalgorithm 51, and carrier 55, to RLC link control layer 10 of mobilestation 15, with multiplexing not being required per se, since only thepacket data stream of second PDP context 22 is transmitted via carrier45 to RLC link control layer 10 of mobile station 15. First PDP context21 would, in this configuration, not access PDP protocol entity 35, incontrast to the example described according to FIG. 3.

If the RRC protocol in mobile station 15 receives carrier configurationmessage 70 and the PDCP protocol entity parameters contained thereincorrespond to the capabilities of mobile station 15, radio resourcecontrol 95 of mobile station 15 will, in addition to carrier 45, alsocreate PDCP protocol entity 35 and configure the PDCP protocol entityparameters correspondingly. Subsequently, the RRC protocol confirms theestablishment of carrier 45 and PDCP protocol entity 35 using a “RadioBearer Setup Complete” message, which represents an acknowledgmentmessage 75 and contains first confirmation signal 55 shown in FIG. 8.Therefore, data transfer is possible via new carrier 45 and via new PDCPprotocol entity 35. If the establishment of carrier 45 and/or PDCPprotocol entity 35 is not possible for any reason, then a “Radio BearerSetup Failure” message is transmitted from mobile station 15 to basestation 16, which may contain information about the reason for thefailed establishment.

PDCP protocol entity 35 which is set up in this manner and uses carrier45 which is also set up, may be more appropriately reconfigured in twoinstances.

In the first case, i.e., if carrier 45 used by PDCP protocol entity 35is also to be reconfigured, it may be advisable to combine bothreconfigurations. A “PDCP Reconfiguration Info” information element,which appears similar or identical to “PDCP Info” information element 40described above and corresponds to second configuration request 41, isinserted in this case into a “Radio Bearer Reconfiguration” messagewhich already exists and is to be transmitted from base station 16 tomobile station 15. In this manner, the compression algorithms used byPDCP protocol entity 35, their compression parameters, and the list ofPDP contexts accessing PDCP protocol entity 35 may be modified and/orreconfigured. The “Radio Bearer Reconfiguration Complete” messagesubsequently sent using RRC protocol from mobile station 15 to basestation 16 then also confirms the reconfiguration of PDCP protocolentity 35 using the reconfiguration of carrier 45.

In the second case, i.e., if carrier 45 used by PDCP protocol entity 35does not have to be reconfigured, it may be advisable to transmit itsown “PDCP Reconfiguration” message used for convergence protocol layer 1of mobile station 15 from base station 16 to mobile station 15, forexample in the form of the “PDCP reconfigure request” message described,which, in addition to second configuration request 41, which containsthe reconfiguration information, also includes the PDCP protocol entityID of PDCP protocol entity 35 or the ID of carrier 45 assigned to it.

The release of PDCP protocol entity 35 may expediently occurautomatically using the release of carrier 45 assigned to it through a“Radio Bearer Release” message.

The configuration of PDCP protocol entity 35 of mobile station 15 usingthe compression algorithms, compression parameters, and multiplexingproperties to be used may be predefined by the base station viacorresponding configuration requests 40, 41, 42 in such a manner thatthe compression algorithms used by PDCP protocol entity 35 to beconfigured may always correspond to a decompression algorithm in basestation 16, in order to be able to decompress the protocol controlinformation or user data compressed by PDCP protocol entity 35 to beconfigured. Furthermore, for the same reason, the compression parameterused by PDCP protocol entity 35 to be configured may also be used fordecompression in base station 16. In addition, the packet data streammultiplexed by PDCP protocol entity 35 to be configured is transmittedas a user data stream to base station 16 and is demultiplexed there as afunction of the multiplexing properties of PDCP protocol entity 35 to beconfigured, in order to be able to distribute the user data streamreceived to the appropriate PDP contexts in network layer 6 of basestation 16.

1.-17. (canceled)
 18. A method for establishing a protocol entity in aconvergence protocol layer of a wireless station, comprising:transmitting a configuration request by the wireless station to a firstwireless station, wherein the configuration request includes: protocolentity parameters, including an identifier for at least one compressionalgorithm, and a protocol entity ID; receiving a confirmationcommunication from the first wireless station confirming establishmentof a protocol entity in the first wireless station, wherein theconfirmation communication includes the protocol entity ID; andconfiguring the protocol entity having the protocol entity ID in theconvergence protocol layer of the wireless station according to thefollowing: configuring the protocol entity to include at least onecompression algorithm identified by the identifier for at least onecompression algorithm, providing an access point to allow communicationbetween a user of the convergence protocol entity and the protocolentity, and providing a second access point to allow communicationbetween the protocol entity and an entity in an RLC (radio link control)layer.
 19. The method of claim 18, wherein the protocol entityparameters include at least one compression parameter and the at leastone compression algorithm is configured to use the at least onecompression parameter.
 20. The method of claim 18, further comprising:subsequently transmitting a reconfiguration request to the firstwireless station, wherein the reconfiguration communication includes theprotocol entity ID and at least one protocol entity parameter that isdifferent from the protocol entity parameters included in theconfiguration request.
 21. The method of claim 18, wherein theconfiguration request is transmitted and the confirmation communicationis received via a control plane and the protocol entity is establishedin a user plane.
 22. The method of claim 18, further comprising: priorto transmitting the configuration request, receiving a communicationidentifying protocol entity parameters supported by the first wirelessstation.
 23. The method of claim 18, wherein the protocol entity IDcorresponds to an identifier for a radio bearer associated with theprotocol entity.
 24. The method of claim 18, wherein the configurationrequest also requests configuration of the radio bearer associated withthe protocol entity.
 25. A wireless station, comprising: a computingdevice; and a mobile wireless communication device connected to thecomputing device, wherein the mobile wireless communication device isconfigured to transmit and receive communications from a mobile wirelessnetwork, wherein the computing device is configured to create aconfiguration request that includes protocol entity parameters includingat least one identifier for a compression algorithm and at least onecompression parameter, and a protocol entity ID, and the mobile wirelesscommunication device is configured to transmit the configuration requestto a first wireless station via the mobile wireless network; wherein themobile wireless communication device is configured to receive aconfirmation communication confirming the establishment of a protocolentity at the first wireless station, wherein the confirmationcommunication includes the protocol entity ID; and wherein the computingdevice is configured to establish a protocol entity having the protocolentity ID in the wireless station according to the following:configuring the protocol entity in a convergence protocol layer of thewireless station so that the protocol entity includes at least onecompression algorithm identified by the at least one identifierconfigured to use the at least one compression parameter, and providingan access point to allow communication between the protocol entity andan entity in an RLC (radio link control) layer.
 26. The wireless stationof claim 25, wherein the computing device is configured to create areconfiguration request that includes the protocol entity ID and atleast one protocol entity parameter different from the configurationrequest, and the mobile wireless communication device is configured totransmit the reconfiguration request to the first wireless station viathe mobile wireless network.
 27. The wireless station of claim 25,wherein the computing device is configured to create a release requestthat includes the protocol entity ID, and the mobile wirelesscommunication device is configured to transmit the release request tothe first wireless station via the mobile wireless network.
 28. Thewireless station of claim 25, wherein the mobile wireless communicationdevice is configured to receive a communication from the first wirelessstation indicating at least one protocol entity parameter supported bythe first wireless station.
 29. The wireless station of claim 25,wherein the computing device is configured to establish the protocolentity in a user plane, and to transmit the configuration request andreceive the confirmation communication via a control plane.
 30. Thewireless station of claim 25, wherein the protocol entity ID correspondsto an identifier for a radio bearer associated with the protocol entity.31. The wireless station of claim 30, wherein the configuration requestalso requests the configuration of the radio bearer associated with theprotocol entity.
 32. The wireless station of claim 25, wherein thecomputing device is further configured to provide a second access pointto allow communication between the protocol entity and a user of theprotocol entity.
 33. A method for establishing a protocol entity in aconvergence protocol layer of a wireless station, comprising:transmitting a radio bearer setup message from the wireless station,wherein the radio bearer setup message includes an identifier for acompression algorithm, a compression parameter, and a protocol entityID; receiving a radio bearer setup complete message confirming theestablishment of a protocol entity at a first wireless station, whereinthe radio bearer setup complete message includes the protocol entity ID;and configuring the protocol entity having the protocol entity ID in theconvergence protocol layer of the wireless station according to thefollowing: configuring the protocol entity to include the compressionalgorithm configured to use the compression parameter, and providing anaccess point to allow communication between an entity in an RLC (radiolink control) layer and the protocol entity.
 34. The method of claim 33,further comprising: receiving a UE (user equipment) capability messagefrom the first wireless station, wherein the UE capability messageindicates that the first wireless station supports the compressionalgorithm and the compression parameter prior to transmitting the radiobearer setup message.
 35. The method of claim 33, further comprising:transmitting a radio bearer reconfiguration message to the firstwireless station, wherein the radio bearer reconfiguration messageincludes the protocol entity ID and identifies a second compressionalgorithm and a second compression parameter, wherein at least one ofthe second compression algorithm and the second compression parameter inthe radio bearer reconfiguration message differs from the compressionalgorithm and the compression parameter included in the radio bearersetup message.
 36. The method of claim 35, further comprising: receivinga radio bearer reconfiguration complete message from the first wirelessstation confirming the reconfiguration of the protocol entity by thefirst wireless station, wherein the radio bearer reconfigurationcomplete message includes the protocol entity ID; and reconfiguring theprotocol entity in the convergence protocol layer of the wirelessstation by configuring the protocol entity to include the secondcompression algorithm configured to use the second compressionparameter.
 37. The method of claim 33, further comprising: transmittinga radio bearer release message to the first wireless station, whereinthe radio bearer release message includes the protocol entity ID. 38.The method of claim 33, wherein the protocol entity is associated withone and only one radio bearer and the protocol entity ID corresponds toan identifier for the radio bearer associated with the protocol entity.39. The method of claim 38, wherein the configuration request alsorequests the configuration of the radio bearer associated with theprotocol entity.
 40. The method of claim 33, wherein configuring theprotocol entity in the convergence protocol layer of the wirelessstation further includes providing a second access point to allowcommunication between the protocol entity and a user of the protocolentity.
 41. A first wireless station, comprising: a computing device;and a mobile wireless communication device connected to the computingdevice, wherein the mobile wireless communication device is configuredto transmit and receive communications from a mobile wireless network,wherein the computing device is configured to create a radio bearersetup message that includes protocol entity parameters including atleast one identifier for a compression algorithm and at least onecompression parameter, and a protocol entity ID, and the mobile wirelesscommunication device is configured to transmit the radio bearer setupmessage to a first wireless station via the mobile wireless network;wherein the mobile wireless communication device is configured toreceive a radio bearer setup complete message confirming theestablishment of a protocol entity at the first wireless station,wherein the radio bearer setup complete message includes the protocolentity ID; and wherein the computing device is configured to establish aprotocol entity having the protocol entity ID in the wireless stationaccording to the following: configuring the protocol entity in aconvergence protocol layer of the wireless station so that the protocolentity includes at least one compression algorithm identified by the atleast one identifier for a compression algorithm configured to use theat least one compression parameter, and providing an access point toallow communication between the protocol entity and an entity in an RLC(radio link control) layer.
 42. The wireless station of claim 41,wherein the computing device is further configured to provide a secondaccess point to allow communication between the protocol entity and auser of the protocol entity.
 43. The wireless station of claim 41,wherein the computing device is configured to establish the protocolentity in a user plane, and to transmit the radio bearer setup messageand to receive the radio bearer setup complete message via a controlplane.
 44. The wireless station of claim 41, wherein the computingdevice is configured to create a radio bearer reconfiguration messagethat includes the protocol entity ID and at least one protocol entityparameter different from the radio bearer setup message, and the mobilewireless communication device is configured to transmit the radio bearerreconfiguration request to the first wireless station via the mobilewireless network.
 45. The wireless station of claim 41, wherein thecomputing device is configured to create a radio bearer release messagethat includes the protocol entity ID, and the mobile wirelesscommunication device is configured to transmit the radio bearer releasemessage to the first wireless station via the mobile wireless network.46. The wireless station of claim 41, wherein the mobile wirelesscommunication device is configured to receive a UE (user equipment)capability information message from the first wireless stationindicating at least one protocol entity parameter supported by the firstwireless station.
 47. The wireless station of claim 41, wherein theprotocol entity ID corresponds to an identifier for a radio bearerassociated with the protocol entity.
 48. The wireless station of claim47, wherein the configuration request also requests the configuration ofthe radio bearer associated with the protocol entity.